Precipitation hardening in Al-Zn-Mg-Al2O3(p) composite

The precipitation hardening of a Al-Zn-Mg-Al2O3(p) composite is explored. It is found that the peak hardness achieved is almost double that of precipitation hardening of Al-Zn-Mg alloy or dispersion strengthening of Al-Zn-Mg with 5% Al2O3(p). Toughness is marginally improved and tensile strength is one and half times that of precipitation hardened Al-Zn-Mg alloys. The ageing time for peak hardness is reduced due to acceleration of formation of precipitate.